Silenes silaaromatics

Similar observations have been made on a few silaaromatics, such as silabenzene and 1-silatoluene, but it is not known which of the many absorption bands observed are associated with the silicon-carbon framework. The same is true for the stable silenes such as (Me3Si)2Si=C(OSi Me3)Ad. Both in solution and the solid state, a number of bands were observed in the region 1300-930 cm-1, but it is not known with certainty which are associated with the Si=C bond. 

With respect to nucleophilic attack, silaaromatics appear to behave in a manner analogous to silenes. The addition of methanol to 1-methylsilabenzene290,326 and to hexamethyl-l,4-disilabenzene314 yields the expected adducts [exclusively 1,4 in the latter case (equation 154)], as does the addition of methanol and tert-butyl alcohol to 1-methyl-2,3,4,5-tetraphenylsilabenzene128. It is possible that the addition occurs on the Dewar isomer of the silaaromatic. The lack of stereospecificity is presumably due to subsequent isomerization of the alkoxysilane in the presence of alcohol. 

---